Entry 1 sense Webster, 1913 Rationalization /(răsh`ŭn*al*ĭ*zā"shŭn)/ · Ra·tion·al·i·za·tion · IPA /ˌræʃənəlaɪˈzeɪʃən/ 01 n. The act or process of rationalizing. 1. The act or process of rationalizing.